How-To: VMware ESX or vSphere – Check CPU’s for 64 bit Compatibility

vSphere 4 requires your processor to be 64 bit. This lesson will show you how to check your existing ESX server to see if it supports 64 bit and the required CPU features in order to run vSphere.

Command from VMware Service Console

On your existing VMware ESX server, you can use a simple command to see if the CPU supports 64 bit and the required "flags" (or features) that vSphere needs.
Open up a SSH session to your ESX server and log in as root.
Then type in:
egrep ‘(vmx|svm)’ /proc/cpuinfo

The flags on the CPU will show if it supports Virtualization Technology (VT) or not. If your system supports VT, then you’ll see vmx or svm in the list of flags.
The vmx flag is for Intel based processors. The svm flag is for AMD based processors.
You’ll see that in the screenshot above, our processor (Intel) does support VT as we have the vmx flag in the results, circled in the red box.

Nothing Listed? Check BIOS

VT technology can still be disabled in your computer’s BIOS, however, so you’ll want to check there to make sure that it hasn’t been disabled. The flags in cpuinfo simply mean that your processor supports it.

Another Method

Another method of checking your CPU’s to see if they support 64 bit and the necessary features for vSphere is to use a utility from VMware. More information about this can be found at this site, which has an excellent write up on it:
http://www.vladan.fr/you-have-to-have-64-bit-hardware-for-vsphere/